Drop inlet for earth-filled dams



April 26, 1955 J- R. BENJAMIN 2,706,893

DROP INLET FOR EARTH-FILLED DAMS Filed May 5, 1950 IN V EN TOR.

United States Patent DROP INLET FOR EARTH-FILLED DAMS Joe] R. Benjamin,Medina, Ohio; Dorothy E. Benjamin, executrix of said Joel R. Benjamin,deceased Application May 5, 1950, Serial No. 160,256

4 Claims. (Cl. 61-18) My invention relates generally to water controldevices and is more particularly directed to a drop inlet forearth-filled dams.

An object of this invention is to provide a one package unit drop inletthat can be prefabricated to meet the acreage and run-off conditions ofa particular water shed area, before the drop inlet is transported tothe dam site.

Another object of this invention resides in providing a drop inlet thatis self supporting, requiring no temporary or permanent auxiliarystructures, and requiring no time consuming and expensive concrete work.

A further object of this invention is to provide a drop inlet with anadjustable anti-swirl plate at the inlet end of the intake stack, topermit the laying of the discharge pipe in any desired direction, andstill keep the antiswirl plate parallel with the center line of the dam.

A still further object of this invention is to provide a drop inlet witha water tight anti-seep plate mounted on the discharge pipe to preventthe seeping of water along the outside surface of the buried dischargepipe.

A still further object of my invention 1s to PIOVldC a drop inlet with abase plate closing the lower end of the intake stack, and extending outbeyond the walls of the stack into the foundation earth, to support theinlet and to overcome buoyancy in deep installations.

Other objects and advantages of this invention will be apparent duringthe course of the following descr ption.

The accompanying drawing is a cross sectlon view of an earth-filled dambuilt up around my drop inlet.

When installing my drop inlet in different localities I may use suchequivalents and alternatives of construction as the exigencies ofvarying conditions may demand without departing from the broad spiritunderlying this invention.

In the drawing an earth-filled dam is shown at 1. It is placed across awatercourse with an upstream slope at 2. This dam is built up around thedrop inlet after it has been assembled and set in place on thefoundation earth level 3 over the core trench 4.

The intake stack 5 has a base plate 6 attached to its lower end. Thearea of the base plate 6 is approximately twice the area of the crosssection of the intake stack 5 to prevent it from sinking down into thefoundation earth. The base plate 6 also prevents the dropping water fromwearing away the foundation earth, and it overcomes buoyancy on deepinstallations.

The adjustable anti-swirl plate 7 welded to attaching collar 8 isfastened to the intake stack 5 by bolts 9 passing thru holes in thecollar brackets 10. This adjustable anti-swirl plate 7 permits thedischarge nipple 11 to be pointed in any desired downstream direction.The face of the anti-swirl plate 7 may thus be set flush with the earthdam 2 and parallel to its center line, so that the plate can perform itsfunction of protecting the earth from erosion by the swirling water atthe entrance of the intake stack 5. Anchor rods 12 attached to theanti-swirl plate 7 extend to the upstream slope at 2.

The discharge tail pipe 13 is attached to the discharge nipple 11 by thewaterproof metal coupling 14. The seal at this junction is obtained bypainting the outside of the discharge nipple 11 and discharge tail pipe13 with an asphalt compound. The waterproof coupling 14 is drawn tightand retained by metal rods 15 wrapped around it and passing thruconventional silo lugs 16. The metal rods 15 are threaded on the ends toreceive nuts that are pulled up against the silo lugs 16.

The upper anti-seep plate 17 and the lower anti-seep plate 18 are eachwelded to a half-collar 19. The two anti-seep plates overlap whenassembled on the discharge tail pipe 13. The half-collars 19 are heldtogether by bolts 20 passing thru collar brackets 21. The purpose of theanti-seep plate is to prevent the removal of foundation earth by waterseeping along the discharge tail pipe 13. The core trench 4 is filledwith a non-porous clay to prevent the seepage of water thru thefoundation earth.

After the drop inlet structure is completely assembled on the foundationearth, the earth dam 1 is filled in up to the level of crest 22,continuing the clay core 23 above the core trench 4.

In summary, it will be understood that the present invention provides anovel drop inlet which includes an adjustable anti-swirl plate, a baseplate, and an antiseep plate furnished as integral parts of a packageunit drop inlet and installed on the apparatus at the time of itsfabrication. This results in the elimination of expensive and timeconsuming concrete work, and makes it financially practical to installsmall water and soil conserving dams and ponds in areas not readilyaccessible.

It is to be understood that the form of my invention, herewith shown anddescribed, is to be taken as a preferred example of the same, and thatvarious changes in the shape, size and arrangement of parts may beresorted to, without departing from the spirit of my invention, or thescope of the subjoined claims.

I claim:

1. A drop inlet construction in combination with an earth-filled damforming a confining Wall or embankment for a body of water, comprisingan upright stack vertically disposed within said earth-filled dam; alaterally extending discharge pipe leading from the lower portion ofsaid stack; a waterproof anti-seep plate mounted on said discharge pipeintermediate the ends thereof; an anti-swirl plate mounted on the upperportion of said stack; a base plate closing the lower end of said stack,said plate being of greater area than the end of the stack so as toextend outwardly beyond the walls of the stack to anchor the drop inletagainst flotation by buoyancy forces exerted on the drop inlet bysurrounding water.

2. A drop inlet construction in combination with an earth-filled damforming a confining wall or embankment for a body of water, comprisingan upright stack vertically disposed within said earth-filled dam; alaterally extending discharge pipe leading from the lower portion ofsaid stack; a base plate closing the lower end of said stack, said platebeing of greater area than the end of the stack so as to extendoutwardly beyond the walls of the stack to anchor the drop inlet againstflotation by buoyancy forces exerted on the drop inlet by surroundingwater.

3. A drop inlet construction in combination with an earth-filled damforming a confining wall or embankment for a body of water, comprisingan upright stack vertically disposed within said earth-filled dam; alaterally extending discharge pipe leading from the lower portion ofsaid stack; an anti-swirl plate mounted on the upper portion of saidstack; a base plate closing the lower end of said stack, said platebeing of greater area than the end of the stack so as to extendoutwardly beyond the Walls of the stack to anchor the drop inlet againstflotation by buoyancy forces exerted on the drop inlet by surroundingwater.

4. A drop inlet construction in combination with an earth-filled damforming a confining wall or embankment for a body of water, comprisingan upright stack vertically disposed within said earth-filled darn; alaterally extending discharge pipe leading from the lower portion ofsaid stack; a waterproof anti-seep plate mounted on said discharge pipeintermediate the ends thereof; a base plate closing the lower end ofsaid stack, said plate being of greater area than the end of the stackso as to extend outwardly beyond the walls of the stack to anchor thedrop inlet against flotation by buoyancy forces exerted on the dropinlet by surrounding water.

(References on following page) References Cited in the file of thispatent UNITED STATES PATENTS Holt et a1. July 22, 1884 Nicholson et a1.Sept. 27, 1892 5 Feltz et a1. July 17, 1906 4 Luce Apr. 8, 1913 SparksDec. 30, 1913 Howard Oct. 8, 1918 Hedrick Nov. 12, 1918 Scott Apr. 5,1932 Roberts Apr. 13, 1948

